package cn.usaiot.server;

public class NV21 {
    /*
     * Refer to https://code.google.com/p/android/issues/detail?id=823
     */
    public static void decodeYUV420SP(int[] rgb, byte[] yuv420sp, int width, int height) {
        final int frameSize = width * height;

        for (int j = 0, yp = 0; j < height; j++) {
            int uvp = frameSize + (j >> 1) * width, u = 0, v = 0;
            for (int i = 0; i < width; i++, yp++) {
                int y = (0xff & ((int) yuv420sp[yp])) - 16;
                if (y < 0) y = 0;
                if ((i & 1) == 0) {
                    v = (0xff & yuv420sp[uvp++]) - 128;
                    u = (0xff & yuv420sp[uvp++]) - 128;
                }
                int y1192 = 1192 * y;
                int r = (y1192 + 1634 * v);
                int g = (y1192 - 833 * v - 400 * u);
                int b = (y1192 + 2066 * u);

                if (r < 0) r = 0; else if (r > 262143) r = 262143;
                if (g < 0) g = 0; else if (g > 262143) g = 262143;
                if (b < 0) b = 0; else if (b > 262143) b = 262143;

                rgb[yp] = 0xff000000 | ((r << 6) & 0xff0000) | ((g >> 2) & 0xff00) | ((b >> 10) & 0xff);
            }
        }
    }

    /*
     * Refer to http://stackoverflow.com/questions/1893072/getting-frames-from-video-image-in-android
     */
    public static void decodeYUV(int[] out, byte[] fg, int width, int height)
            throws NullPointerException, IllegalArgumentException {
        int sz = width * height;
        if (out == null)
            throw new NullPointerException("buffer out is null");
        if (out.length < sz)
            throw new IllegalArgumentException("buffer out size " + out.length
                    + " < minimum " + sz);
        if (fg == null)
            throw new NullPointerException("buffer 'fg' is null");
        if (fg.length < sz)
            throw new IllegalArgumentException("buffer fg size " + fg.length
                    + " < minimum " + sz * 3 / 2);
        int i, j;
        int Y, Cr = 0, Cb = 0;
        for (j = 0; j < height; j++) {
            int pixPtr = j * width;
            final int jDiv2 = j >> 1;
            for (i = 0; i < width; i++) {
                Y = fg[pixPtr];
                if (Y < 0)
                    Y += 255;
                if ((i & 0x1) != 1) {
                    final int cOff = sz + jDiv2 * width + (i >> 1) * 2;
                    Cb = fg[cOff];
                    if (Cb < 0)
                        Cb += 127;
                    else
                        Cb -= 128;
                    Cr = fg[cOff + 1];
                    if (Cr < 0)
                        Cr += 127;
                    else
                        Cr -= 128;
                }
                int R = Y + Cr + (Cr >> 2) + (Cr >> 3) + (Cr >> 5);
                if (R < 0)
                    R = 0;
                else if (R > 255)
                    R = 255;
                int G = Y - (Cb >> 2) + (Cb >> 4) + (Cb >> 5) - (Cr >> 1)
                        + (Cr >> 3) + (Cr >> 4) + (Cr >> 5);
                if (G < 0)
                    G = 0;
                else if (G > 255)
                    G = 255;
                int B = Y + Cb + (Cb >> 1) + (Cb >> 2) + (Cb >> 6);
                if (B < 0)
                    B = 0;
                else if (B > 255)
                    B = 255;
                out[pixPtr++] = 0xff000000 + (B << 16) + (G << 8) + R;
            }
        }

    }

    public static int[] yuv2rgb(byte[] yuv, int width, int height) {
        int total = width * height;
        int[] rgb = new int[total];
        int Y, Cb = 0, Cr = 0, index = 0;
        int R, G, B;

        for (int y = 0; y < height; y++) {
            for (int x = 0; x < width; x++) {
                Y = yuv[y * width + x];
                if (Y < 0) Y += 255;

                if ((x & 1) == 0) {
                    Cr = yuv[(y >> 1) * (width) + x + total];
                    Cb = yuv[(y >> 1) * (width) + x + total + 1];

                    if (Cb < 0) Cb += 127; else Cb -= 128;
                    if (Cr < 0) Cr += 127; else Cr -= 128;
                }

                R = Y + Cr + (Cr >> 2) + (Cr >> 3) + (Cr >> 5);
                G = Y - (Cb >> 2) + (Cb >> 4) + (Cb >> 5) - (Cr >> 1) + (Cr >> 3) + (Cr >> 4) + (Cr >> 5);
                B = Y + Cb + (Cb >> 1) + (Cb >> 2) + (Cb >> 6);

                // Approximation
//				R = (int) (Y + 1.40200 * Cr);
//			    G = (int) (Y - 0.34414 * Cb - 0.71414 * Cr);
//				B = (int) (Y + 1.77200 * Cb);

                if (R < 0) R = 0; else if (R > 255) R = 255;
                if (G < 0) G = 0; else if (G > 255) G = 255;
                if (B < 0) B = 0; else if (B > 255) B = 255;

                rgb[index++] = 0xff000000 + (R << 16) + (G << 8) + B;
            }
        }

        return rgb;
    }

    public static int[] yuv2rgbaInt(byte[] yuv, int width, int height) {
        int total = width * height;
        int[] rgb = new int[total];
        int Y, Cb = 0, Cr = 0, index = 0;
        int R, G, B;

        for (int y = 0; y < height; y++) {
            for (int x = 0; x < width; x++) {
                Y = yuv[y * width + x];
                if (Y < 0) Y += 255;

                if ((x & 1) == 0) {
                    Cr = yuv[(y >> 1) * (width) + x + total];
                    Cb = yuv[(y >> 1) * (width) + x + total + 1];

                    if (Cb < 0) Cb += 127; else Cb -= 128;
                    if (Cr < 0) Cr += 127; else Cr -= 128;
                }

                R = Y + Cr + (Cr >> 2) + (Cr >> 3) + (Cr >> 5);
                G = Y - (Cb >> 2) + (Cb >> 4) + (Cb >> 5) - (Cr >> 1) + (Cr >> 3) + (Cr >> 4) + (Cr >> 5);
                B = Y + Cb + (Cb >> 1) + (Cb >> 2) + (Cb >> 6);

                // Approximation
//				R = (int) (Y + 1.40200 * Cr);
//			    G = (int) (Y - 0.34414 * Cb - 0.71414 * Cr);
//				B = (int) (Y + 1.77200 * Cb);

                if (R < 0) R = 0; else if (R > 255) R = 255;
                if (G < 0) G = 0; else if (G > 255) G = 255;
                if (B < 0) B = 0; else if (B > 255) B = 255;

                rgb[index++] = 0x00000000 + (R << 24) + (G << 16) + (B<<8);
            }
        }

        return rgb;
    }

    public static byte[] yuv2rgba(byte[] yuv, int width, int height) {
        int total = width * height;
        //int[] rgb = new int[total];
        byte[] rgb = new byte[total*4];
        int Y, Cb = 0, Cr = 0, index = 0;
        int R, G, B;

        for (int y = 0; y < height; y++) {
            for (int x = 0; x < width; x++) {
                Y = yuv[y * width + x];
                if (Y < 0) Y += 255;

                if ((x & 1) == 0) {
                    Cr = yuv[(y >> 1) * (width) + x + total];
                    Cb = yuv[(y >> 1) * (width) + x + total + 1];

                    if (Cb < 0) Cb += 127; else Cb -= 128;
                    if (Cr < 0) Cr += 127; else Cr -= 128;
                }

                R = Y + Cr + (Cr >> 2) + (Cr >> 3) + (Cr >> 5);
                G = Y - (Cb >> 2) + (Cb >> 4) + (Cb >> 5) - (Cr >> 1) + (Cr >> 3) + (Cr >> 4) + (Cr >> 5);
                B = Y + Cb + (Cb >> 1) + (Cb >> 2) + (Cb >> 6);

                // Approximation
//				R = (int) (Y + 1.40200 * Cr);
//			    G = (int) (Y - 0.34414 * Cb - 0.71414 * Cr);
//				B = (int) (Y + 1.77200 * Cb);

                if (R < 0) R = 0; else if (R > 255) R = 0;
                if (G < 0) G = 0; else if (G > 255) G = 0;
                if (B < 0) B = 0; else if (B > 255) B = 0;

                //rgb[index++] = 0x00000000 + (R << 24) + (G << 16) + (B<<8);
                //rgb[index++] = (byte)R;
                //rgb[index++] = (byte)G;
                //rgb[index++] = (byte)B;
                //rgb[index++] = 0;
                rgb[index++] = (byte)R;
                rgb[index++] = (byte)G;
                rgb[index++] = (byte)B;
                rgb[index++] = 0;
            }
        }

        return rgb;
    }
}